Given that increasing numbers of people embark on international and domestic air travel every year, the issue of venous thromboembolism (VTE) in air travellers is of significant concern. In March 2001, the World Health Organization convened an international meeting on air travel and venous thrombosis at which experts on VTE and representatives of airline companies, the International Air Transport Association (IATA), the International Civil Aviation Organization (ICAO), the European Commission and consumer groups participated. The objectives were to review the scientific information concerning air travel and VTE, identify gaps in knowledge and develop priority areas for research. This booklet presents the final findings of phase I of this report.